Diabetes mellitus, other medical conditions and pancreatic cancer: a case-control study.

BACKGROUND

Diabetes and other medical conditions have been related to pancreatic cancer, but time risk quantification is unsettled.

METHODS

We combined data from two case-control studies conducted in Italy, including 688 pancreatic cancer cases and 2204 controls. All subjects were interviewed by trained interviewers during their hospital stay. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using multiple logistic regression.

RESULTS

Overall, 103 cases (15%) and 125 controls (5.7%) reported a history of diabetes. The OR for pancreatic cancer was more pronounced among those diagnosed with diabetes in the previous 2 years (OR = 5.17; 95% CI = 2.71-9.87) than among those with diabetes diagnosed more than 2 years ago (OR = 2.35; 95% CI = 1.70-3.26). The ORs remained significantly elevated 2-4 years (OR = 3.81; 95% CI = 2.07-7.04) and 5-9 years (OR = 3.75; 95% CI = 2.13-6.59) since diagnosis of diabetes, after which a non-significant 20% increased risk for pancreatic cancer was observed. As compared to non-diabetic non-smokers, the OR was 1.85 among non-diabetic current smokers, 2.17 among diabetic never/former smokers, and rose to 4.67 among diabetic current smokers, indicating a multiplicative effect between these two risk factors. Pancreatic cancer was significantly associated with pancreatitis, primarily among those diagnosed within 2 years (OR = 7.16; 95% CI = 2.25-22.78). In addition, the ORs were elevated for cholelithiasis (3.53; 95% CI = 1.67-7.45) and gastroduodenal ulcer (3.16; 95% CI = 1.14-8.73) only among those diagnosed within the past 2 years.

CONCLUSIONS

Diabetes is associated with heightened risk of pancreatic cancer. The association is significant for diabetes diagnosed up to 10 years before pancreatic cancer.